During the heat of the 2012 primaries, CPAC is where Romney described himself as a “severely conservative governor” in an ad-libbed effort to shore up his right flank that only raised fresh doubts about his authenticity.

“He’s kind of last year. I’m ready for some new blood,” said Laurie Pettengill, 55, a former New Hampshire state representative. “The Beltway doesn’t want to let go of a lot of things … You shake your head and say, ‘C’mon!’”

Pettengill supported Newt Gingrich in the first-in-the-nation primary but backed Romney after he secured the nomination. Now she talks with friends about what might have been.

“People have a little bit of anger that he never went after the jugular. He is a nice gentleman [but] there wasn’t enough fight,” she said. “Newt just knows how to pounce.”

The banner above the podium where Romney will speak declares the theme of the conference: “America’s Future: The Next Generation of Conservatives.” Romney, who turned 66 on Tuesday, is part of neither.

“He’s getting kind of old now,” said Zachary Pohl, 20, an Ohio State University student who backed Romney in 2008 and 2012. “I’m not going to lie about it.”

The conference draws a mix of millennials looking to network with like-minded true believers, baby boomers looking to brag about their role in the Reagan Revolution and politicians looking to build grassroots support.

Five years ago, at CPAC in 2008, Romney ended his campaign against John McCain for the GOP nomination.

“CPAC has been very good to Mitt Romney over the years, and this is a chance for him to express his appreciation for all that support,” longtime adviser Eric Fehrnstrom emailed in response to a question about the focus of the speech.

The Republican base never felt completely comfortable with Romney. They accepted him only after exhausting the alternatives, from Rick Perry to Newt Gingrich and Rick Santorum, driven as much by a desire to deny President Barack Obama a second term as anything else.

Romney won the straw poll four of the past six years with the help of operatives quietly maneuvering to bring in supporters. The victory last year, on the same day Romney won the Maine caucuses, helped slow Santorum’s momentum coming out of Missouri, Minnesota and Colorado.